Numerical investigation of the partial oxidation in a two-stage downdraft gasifyer

International audienceno abstrac

Preparation of Pt/γ-Al2O3 catalyst coating in microreactors for catalytic methane combustion

International audience• γ-Al 2 O 3 washcoated on FeCrAlloy substrates exhibited excellent adhesion. • γ-Al 2 O 3 particle size and pH are important factors affecting the slurry stability. • Polyvinyl alcohol as the binder effectively enhanced the washcoat adhesion. • Pt/γ-Al 2 O 3 coated in microreactors catalyzed methane combustion efficiently. • Temperature and oxygen-to-methane ratio greatly affected the methane conversion

A review on catalytic methane combustion at low temperatures:Catalysts, mechanisms, reaction conditions and reactor designs

International audienceNatural gas (with methane as its main component) provides an attractive energy source because of its large abundance and its high heat of combustion per mole of carbon dioxide generated. However, the emissions released from the conventional flame combustion (essentially NO x) have harmful impacts on the environment and the human health. Within the scope of rational and clean use of fossil energies, the catalytic combustion of natural gas appears as one of the most promising alternatives to flammable combustion. The presence of catalysts enables complete oxidation of methane at much lower temperatures (typically 500 � C), so that the formation of pollutants can be largely avoided. This work presents a literature review on the catalytic methane combustion. Various aspects are discussed including the catalyst types, the reaction mechanisms and kinetic characteristics, effects of various influencing operational factors and different reactor types proposed and tested. This paper may serve as an essential reference that contributes to the development of well-designed reactors, equipped with appropriate catalysts, and under well-handled operating conditions to realize the favorable (kinetic) performance, for their future applications and propagation in different industrial sectors

Catalytic methane combustion in plate-type microreactors with different channel configurations:An experimental study

International audienceThis paper presents an experimental study on the catalytic methane combustion (CMC) in platetype microreactors with wall-coated Pt/γ-Al2O3 catalyst. Firstly, the influence of different operational conditions and coating properties on the CMC in the straight parallel-channel microreactor has been investigated. A specific catalyst loading of 57.6 g m-2 was found to yield the highest methane conversion over 3.5 wt% Pt/γ-Al2O3. A higher or lower loading tended to decrease the methane conversion due to either the limited internal diffusion through the thicker coating layer or insufficient active sites in the thinner coating layer. Then, the above microreactor was compared with other five different geometries, including cavity, double serpentine microchannels, obstacled microchannels, meshed circuit and vascular network. The double serpentine microchannel geometry presented the highest methane conversion (especially at

Experimental investigation on puffing and micro-explosion occurrence of water in rapeseed oil emulsions droplets : effect of the surfactant concentration

[EN] In this paper, the assessment of puffing and micro-explosion occurrence in emulsion drops with different water percentage is studied. The emulsified fuels are formulated using micro channel emulsifier, rapeseed oil and diesel fuel as continuous phase, as well as water and Sorbitan Sesquioleate as surfactant. The formulated dispersed systems are covered under different experimental factors such as water ratio and surfactant percentage. The puffing occurrence is reported in all emulsified fuels tested (i.e. with and without surfactant). A sudden puffing and highest number of occurrence is noted when the water amount increases in all emulsified fuels. The micro-explosion phenomenon is only noted in emulsified fuel formulated without surfactant.The authors wish to express their acknowledgement to the Centre National de la Recherche Scientifique (CNRSFrance) and Flemish Interuniversity Council’s (VLIR) University Development Cooperation, funding a South Initiatives Program entitled “Emulsified systems for biofuels. Assessment of their performance in diesel engines”, because of their support to this research.Melo-Espinosa, EA.; Bellettre, J.; Tarlet, D.; Piloto-Rodriguez, R.; Verhelst, S. (2017). Experimental investigation on puffing and micro-explosion occurrence of water in rapeseed oil emulsions droplets. Effect of the surfactant concentration. En Ilass Europe. 28th european conference on Liquid Atomization and Spray Systems. Editorial Universitat Politècnica de València. 822-829. https://doi.org/10.4995/ILASS2017.2017.4594OCS82282

Viscosity effects on liquid-liquid dispersion in laminar flows

Efficiency of liquid/liquid dispersion is an important stake in numerous sectors, such as the chemical, food, cosmetic and environmental industries. In the present study, dispersion is achieved in an open-loop reactor consisting of simple curved pipes, either helically coiled or chaotically twisted. In both configurations, we investigate the drop breakup process of two immiscible fluids (W/O) and especially the effect of the continuous phase viscosity, which is varied by addition of different fractions of butanol in the native sunflower oil. The global Reynolds numbers vary between 40 and 240, so that the flow remains laminar while the Dean roll-cells in the bends develop significantly. Different fractions of butanol are added to the oil in each case to examine the influence of the continuous phase viscosity on the drop size distribution of the dispersed phase (water). When the butanol fraction is decreased, the dispersion process is intensified and smaller drops are created. The Sauter mean diameters obtained in the chaotic twisted pipe are compared with those in a helically coiled pipe flow. The results show that chaotic advection intensifies the droplet breakup till 20% in droplet size reduction, and also reduces polydispersity

Emulsification en continu avec un microsystème en vue de l'encapsulation d'antioxydants

National audienceRESUME Cette étude porte sur une problématique qui intéresse le secteur des compléments alimentaires et celui de la santé. Des chercheurs ont récemment développé un protocole [1] permettant une extraction et une « encapsulation » par émulsification d'antioxydants naturels (astaxanthine,  carotènes ou lycopènes), pour la plupart issus de microalgues, basées sur l'emploi de molécules plus respectueuses de l'environnement et peu couteuses. Ce protocole est à ce stade réalisé manuellement, en réacteur batch et met en jeu des petits volumes. Il serait intéressant de le transposer vers un procédé fonctionnant en continu permettant de traiter des volumes plus importants, de manière plus reproductible et en limitant le contact de la phase lipidique avec l'oxygène. L'idée proposée ici est de mettre en oeuvre un micromélangeur [2] développé par les laboratoires GEPEA et LTeN afin d'étudier son potentiel vis-à-vis de ce type d'application. Ce type de micromélangeur (Figure 1), basé sur un mélange intime des fluides dans un volume très réduit (< 1mL) et avec un temps de séjour très faible (de l'ordre de la milliseconde), peut être une solution intéressante au regard des contraintes liées à cette application. Les débits maximaux atteints par ce dispositif sont de l'ordre de 600 mL/min ce qui est compatible avec une production à pteite ou moyenne échelle. D'autre part, s'agissant de la perspective de l' « usine du futur », la mise en oeuvre de systèmes intensifiés s'inscrit dans une dynamique de développement de procédés miniaturisés et globalement plus économes en énergie. Cette étude se concentre dans un premier temps sur des tests de formulation et d'émusification à l'échelle paillasse avec un système fonctionnant en batch, de type rotor-stator, en faisant varier divers paramètres tels que la vitesse et le temps de rotation du rotor, les proportions des deux phases et la composition de celles-ci. Cette première phase de l'étude permet d'affiner le choix de formulations d'émulsions de type huile dans eau offrant une bonne stabilité. Des essais sont ensuite menés avec le micromélangeur sur les formulations les plus intéressantes vis-à-vis de l'application visée. Les émulsions ainsi obtenues avec les deux systèmes sont alors comparées en termes de distribution granulométrique et de stabilité au cours du temps. Dans un dernier temps, l'étude s'intéresse à l'incorporation de  carotènes dans la formulation avec en particulier l'évaluation de l'efficacité de rétention des  carotènes dans la phase lipidique et l'étude de la stabilité chimique des émulsions obtenues. MOTS-CLES DU THEME Procédés émergents, Microprocédés, Microfluidique. MOTS-CLES LIBRES Emulsion, Fractionnement, procédé continu, antioxydan

Design of a System of Internal Control Traceability Merchandise on Distribution Center Pharmaceutical Industry

Este artículo tiene como propósito presentar el diseño de un sistema de trazabilidad de cajas para el control de mercancía, en un centro de distribución del sector farmacéutico, donde actualmente se generan problemas en los despachos a sus clientes, constantes perdidas de cajas en los pedidos y envíos con inconsistencias, generando afectaciones económicas y reputaciones con sus clientes. Para lo anterior, se realizó la identificación de los objetos rastreables (cajas), actores inmersos y descripción del seguimiento interno con mejoras tecnológicas, lecturas de códigos de barras EAN 128 a través de Terminales de Radiofrecuencia (TRF) registrando toda la información de tiempos y cambios de estado en el sistema SISLOG.This article aims to present the design of a system of traceability of boxes to control merchandise in a distribution center in the pharmaceutical sector, which currently problems generated in shipments to customers, constant losses of boxes in orders and shipments inconsistencies, causing economic disruption and reputations with customers. For this, the identification of trackable objects (boxes), players involved and description of the internal follow up with technological improvements, readings EAN bar codes 128 through terminals Radiofrequency (TRF) recording all the time information it was made and state changes in the SISLOG system

Construction and characterization of two BAC libraries representing a deep-coverage of the genome of chicory (Cichorium intybus L., Asteraceae)

<p>Abstract</p> <p>Background</p> <p>The Asteraceae represents an important plant family with respect to the numbers of species present in the wild and used by man. Nonetheless, genomic resources for Asteraceae species are relatively underdeveloped, hampering within species genetic studies as well as comparative genomics studies at the family level. So far, six BAC libraries have been described for the main crops of the family, <it>i.e</it>. lettuce and sunflower. Here we present the characterization of BAC libraries of chicory (<it>Cichorium intybus </it>L.) constructed from two genotypes differing in traits related to sexual and vegetative reproduction. Resolving the molecular mechanisms underlying traits controlling the reproductive system of chicory is a key determinant for hybrid development, and more generally will provide new insights into these traits, which are poorly investigated so far at the molecular level in Asteraceae.</p> <p>Findings</p> <p>Two bacterial artificial chromosome (BAC) libraries, CinS2S2 and CinS1S4, were constructed from <it>Hin</it>dIII-digested high molecular weight DNA of the contrasting genotypes C15 and C30.01, respectively. C15 was hermaphrodite, non-embryogenic, and <it>S</it>₂<it>S</it>₂for the <it>S</it>-locus implicated in self-incompatibility, whereas C30.01 was male sterile, embryogenic, and <it>S</it>₁<it>S</it>₄. The CinS2S2 and CinS1S4 libraries contain 89,088 and 81,408 clones. Mean insert sizes of the CinS2S2 and CinS1S4 clones are 90 and 120 kb, respectively, and provide together a coverage of 12.3 haploid genome equivalents. Contamination with mitochondrial and chloroplast DNA sequences was evaluated with four mitochondrial and four chloroplast specific probes, and was estimated to be 0.024% and 1.00% for the CinS2S2 library, and 0.028% and 2.35% for the CinS1S4 library. Using two single copy genes putatively implicated in somatic embryogenesis, screening of both libraries resulted in detection of 12 and 13 positive clones for each gene, in accordance with expected numbers.</p> <p>Conclusions</p> <p>This indicated that both BAC libraries are valuable tools for molecular studies in chicory, one goal being the positional cloning of the <it>S</it>-locus in this Asteraceae species.</p